A Miniaturized Broadband Planar Gysel High Power Combiner for Power Amplifiers

Abstract

This paper presents a new design of a miniaturized broadband planar Gysel combiner for high-power applications. Mender lines are used to provide size reduction and maintain broadband performance. A prototype is designed, simulated, fabricated, and measured to operate at the frequency band from 1 to 1.6 GHz (46% fractional bandwidth) to fulfill the requirements of L-band radar applications. The measured return loss is better than 15 dB ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{VSWR}\leq 1.5$</tex> ), the insertion loss is less than 0.4 dB, and the isolation between input ports is better than 15 dB. The power combiner provides a small size and low profile with a high power handling capability level (up to 6 KW peak power). Besides, it offers excellent amplitude and phase imbalances which makes the proposed design an excellent candidate for the combining stages in power amplifier modules. Measurements show a very good agreement with simulations which verifies the proposed idea and design methodology.